The invention relates to apparatus for the formation and/or enlarging of generally horizontal bores for the mining of coal, ore and the like. In the past, coal has often been mined with conventional auger-miners (such as shown in U.S. Pat. No. 2,784,955) and the like by boring a generally circular cross-section bore into a coal seam. Bores must be spaced far enough from each other to make sure that collapse of the bores does not occur, however, in many older mines these bores are much farther apart than necessary. In mining in such a method, generally the maximum amount of coal is not recovered from an area both because of the shape of the bores and because the area in between bores is wasted.
According to the present invention, apparatus is provided for enlarging pre-existing bores both by changing the cross-sectional shape and the cross-sectional area thereof, and additionally for forming new bores and removing ore during both movement of the mining machine into and out from the bore (the invention is also applicable to underground mining). Conventional mining machines, such as shown in U.S. Pat. Nos. 2,784,955; 3,105,677; 3,121,558; 3,190,698; 3,210,123; and 3,333,898 are capable only of mining during movement of the mining machine into a formation to form a bore therewith, and not during withdrawal of the machine. The machine and method according to the present invention result in the advantages of less wasted set-up time and the like for mining with a machine of a given size, the mining of larger bores with a machine of a given size, and the capacity to retrieve coal, ore and the like from bores that have previously been made, which coal, ore and the like has been up to now unusable. All of this can be accomplished with safety since operators are never required to go into the bores being formed or enlarged.
According to the present invention, a mining machine is provided that has a non-rotatable body member in line with a conveying means, and a pair of wing-cutters. The wing-cutters are generally formed by rotatable cutting drums pivotally mounted on lever arms to the body member, and generally driven by cutting chains or the like. During movement of the machine into a pre-existing bore, the wing-cutters are in a position substantially in line with the body member and the conveyor, the mining as a whole presenting a cross-sectional area about the same as or slightly less than that of the pre-existing bore. Once far enough into the bore, the wing-cutters are then moved to a position wherein they are disposed outwardly with respect to the body member, and they are held in that outward position while the rotatable drum cutting portions thereof are normally rotated in a direction outwardly from the body member, each drum rotating in a different direction than the other. The machine is withdrawn with the wing-cutters in this position, and cutting takes place the whole time during withdrawal, the coal or the like being thrown toward the conveying means, which preferably comprises an auger.
For both in and out cutting, preferably a pilot cutting head is provided for the machine, in line with the body member and the conveying means. The pilot head preferably is a conventional type such as disclosed in U.S. Pat. No. 2,784,955, the disclosure of which is hereby incorporated by reference in the present application. Also, the chains which drive the cutting drums preferably are cutting chains and they may be arranged so that a circular hole of diameter D cut by the pilot cutting head is enlarged during in-cutting to a square [rectangular] hole of dimension D sides.
In order to increase the efficiency of the coal transport during out-cutting means for moving the coal cut by the wing-cutters during out-cutting towards the sides of the bore may be provided Such sideward moving means may include shield means associated with each of the wing-cutters and mounted for pivotal movement with the wing-cutters, the shield means comprising a shield associated with each cutting drum and extending essentially the length of the cutting drum (but not overlapping the cutting chain associated with the cutting drums), and termination of each shield is coplanar with the associated cutting drum axis and the parellel axis associated with the body member about which the cutting drum is pivotal. The coal moving means also includes a generally conical member coaxial with the shaft for rotation of the pilot head and mounted between the pilot head and the wing-cutters. Means for stabilizing the body member may include a pair of wheel sets spaced along the length of the conveying means, and a pair of right angle or vertical guide members vertically displaced from the wheel structure. The back-wheel set may comprise a pair of vertically spaced wheels, the upper wheel of which engages the roof and is vertically adjustable. Where the conveying means is in auger having a central shaft, the auger sections that are added to the auger may have a pair of stabilizing support assemblies with skids or wheels and a power source conduit may extend through the shaft or between corresponding legs of the stabilizing supports.
If roof cutting is desired for seams that are higher than may be cut by the pilot cutting head and the wing-cutters, cutting means for cutting the roof of the bore may be provided. Such cutting means may include a cutting drum rotatable about a generally horizontal axis, and means for rotating the cutting drum about the axis, such rotating means including a mounting for a horizontal shaft which mounting is stationary with respect to the body member, and a pair of chain cutters disposed between a gear end of the cutting drum and a gear mounted at an end of the shaft associated with the stationary mounting. Means -- such as hydraulic cylinders -- may be provided for horizontally moving cutters at the ends of the cutting drum with respect to the mounting and the body members so that the roof cutting can be effected during out-cutting to produce a wider roof cut than during in-cutting. Additionally, arms mounting the cutting drum are associated with a hydraulic cylinder or the like for pivoting the cutting drum with respect to the stationary mounting to adjust the vertical position of the cutting drum.
Conveying means may be associated with the cutting head according to the invention that save energy over an auger conveyor, yet are useful for conveying coal from the locations in which the machine according to the present invention is employed. Such conveying means include a double helix distributor member mounted on the pilot cutting head shaft posterior of the wind-cutters for agitating and distributing the cut coal. Scoop means are disposed posterior of the distributor member and have a bottom portions substantially abutting the bore floor and extending posteriorly therefrom at a positve angle, and having side members that funnel toward the shaft. A conveyor belt is disposed posterior of the scoop means, the scoop means bottom portion and side members funnelling toward the conveyor belt and a top transporting surface of the conveyor belt being disposed adjacent the termination of the scoop means bottom portion and side members. The drive shaft is vertically spaced from the conveyor top portion in non-interfering relationship therewith. Preferably, the angle formed between the scoop means bottom and the floor is 12.degree., but in any event it is preferably less than 14.degree.. An auger section may be provided on the shaft posterior of the double helix, the auger section having continuously decreasing flight diameter from the double helix toward the scoop means, the auger section disposed above the bottom portion of the scoop means for conveying cut coal up the scoop means. The conveyor belt preferably includes an anterior portion having rollers adjacent the termination of the scoop means, and having posterior portions comprising forming a trough for supporting the conveyoyr belt surface. Add-on sections are provided for the shaft and the conveyor belt, each add-on section including vertically extending supports for supporting the limber rollers, stabilizing means for engaging the formed bore, and a bushing collar supported by the vertical extending supports for mounting the shaft.
It is the primary object of the present invention to provide an improved apparatus for the mining of coal, ore and the like. This and other objects of the invention will become apparent from an inspection of the detailed description of the invention, and from the appended claims.